Wednesday, June 20, 2007

2007 Virginia Field Day Notes

Gerald's Post:
This past Saturday I attended the the MGGA Summer Field Day at Summerseat Vineyard just down the road from us in Charlotte Hall. Pat Isle, the vineyard manager, hosted the event.

Summerseat dates back to 1732 and is unusual for SoMD in that it was an interior plantation. Most plantations were located on the water, as a necessity for transportation. The primary dwelling is listed in the Marland HIstorical Trust survey no. SM-181. The property is now held by a non-profit organization dedicated to it's preservation and promotion of mankind's connection with the land, plants and animals.

The current vineyard at Summerseat is a 1/2 acre testing site with many different varieties planted, usually in groups of four vines, although there are a large number of Foch, Vidal Blanc, Norton, and Chambourcin. Smaller numbers of Viognier, Sangiovese, Petite Verdot, Vignoles, Dolcetto, Mavasia Bianca, Nebbiola, Petite Sirah, Cabernet Franc, and Barbera.

There was some Shiraz, but it was replaced, as it didn't do very well.

The Viognier looked good, although crop can be light. Joe Fiola commented that BUD NECROSIS often occurs with this variety in the fall, and is generally not the result of frost or freeze in the late spring.

Pat noted his Grape Root Borer populations and control methods. I have not investigated this on our site, but plan to find out how to do this.

Joe Fiola of UMD gave a talk on vineyard management practices:
  • Tight-clustered variety prevention
    pinch off the bottom of the cluster before berry-touch (now). When it rains, the water will run out the bottom of the cluster instead of collecting inside the cluster and promoting mold development.
  • Bunch thinning
    Should be done just before veraison to get to final cropping levels. Drop all clusters on half-length shoots, as these will not ripen anyway.
  • Spraying
    pH of water can make a difference in efficacy. Read product labels for details. Need to test pH.
  • Nitrogen
    Vines use stored N up to bloom. Then must get it from the ground (or leaves via foliar fertilization). Bloom/post bloom is optimal time for N application. Petiole analysis is the best means of determining nutrient requirements in the vine.
  • Three Reasons for leaf pulling
    • 1) Ripen clusters
    • 2) The buds lowest on the shoots this year will be the fruiting shoots next year, but will only be fruitful if they don't get shaded this year.
    • 3) Airflow and sunshine inhibits disease conditions. There are two kinds of sunlight: Morning (cool) sun, and Afternoon (hot) sun. The cool morning sun is good for clusters, as it dries them quickly and does not heat or burn the clusters. Afternoon sun tends to keep the clusters warm longer, preventing development of character flavors, and can potentially burn the clusters. With this in mind, leaf-pulling to open the canopy and expose the clusters is a two-stage process. Leaves on the east side of the rows should be pulled 2 to 4 weeks post bloom, which is now. Leaves on the west side of the rows should be pulled just prior to veraison.
  • Canopy density
    A good rule of thumb: When looking through a row at someone on the other side, you should be able to see what color shirt they have on, but not be able to identify the person.
Next came a short MGGA business meeting.

Bruce Perrygo mentioned the grape growing survey results are available online at and includes variety recommendations.

Emily Johnson gave an update on the CPPP. Due to Homeland Security rules changes, there are certain pesticides that cannot be broken out of their packages for distribution. This means that a few products require individuals to purchase unreasonable quantities, unless some legal method of breaking up the packages can be found. The example given was Quintec, which comes in a ten-bottle package, but which a single bottle would do for one vineyard for an entire season.

Jan Ricki gave a treasurer update. There is grant money available from the state for grape growing related projects, but they have not recieved many proposals on how to spend it. Send in ideas.

Joe Fiola hosted organoleptic testing of varieties grown in the UMD test vineyard in Upper Marlboro. I sampled a very unusual Pinot Grigio. It had a fruity aroma and pronounced apple taste. While not what people think of this variety, Joe commented this style was quite common in Southern France and NW Italy. Ann DeMarsay of UMD gave a talk on bunch rots and passed out samples of common diseases.

Primary pathogens are things that can infect healthy grapes - only fungi can do this. Common ones are: Phomopsis, Black Rot, Botrytis, Ripe Rot, Bitter Rot, Macrophma Rot. Secondary pathogens require an entry point caused by a primary pathogen, mechanical injury, or wildlife damage (bird pecks). Management practices include: Planting resistant varieties, loose clusters, less vigorous, hybrids, natives. Good canopy mgmt - shoot thinning, hedging, leaf pulling, cluster thinning. 7-10 day spray schedule through post-bloom 10-14 day schedule thereafter, depending on disease pressure and weather. PM resistance is documented to FLINT after 15 - 20 total sprays. (I use this one and have about 6 total so far.) PM is becoming resistant to SI's (that's a class of fungicide, of which Nova is one. I use Nova intermittently.) Ben Beale of the Cooperative Extension Service gave a very good spraying demo, including different types of spraying equipment. Everything from backbacks to airblast sprayers. Demonstrated proper personal protective equipment and processes, and sprayer/tractor calibration. Pat Isle's sprayer was on display. He has a similar one to ours, but has modified it with a single verticle boom with three nozzles. Looked great. He pulls a 50 gallon tank with a 23 hp riding mower. I spoke one-on-one with Dr DeMarsey about our Tinta Cao vines that have fan leaves. I offered to send her pics of them and have done so. She mentioned that certain varieties of blueberries do well in the heat. I always thought they were more of a cold weather crop. She received her doctorate for research on blueberries, so she probably knows something about it.

That's it for now. If you made to the end of this message I commend you on your fortitude.

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